High-Throughput Screening Assays

Drug resistant tuberculosis has threatened all the advances that have been made in TB control at the global stage in the last few decades. DNA gyrase enzymes are an excellent target for antibacterial drug discovery as they are involved in essential functions like DNA replication. Here we report, a successful application of high throughput virtual screening (HTVS) to identify an inhibitor of Mycobacterium DNA gyrase targeting the wild type and the most prevalent three double mutants of quinolone resistant DNA gyrase namely A90V+D94G, A74S+D94G and A90V+S91P.

There is considerable interest in identifying small, drug-like compounds that slow aging in multiple species, particularly in mammals. Such compounds may prove to be useful in treating and retarding age-related disease in humans. Just as invertebrate models have been essential in helping us understand the genetic pathways that control aging, these model organisms are also proving valuable in discovering chemical compounds that influence longevity.

The chronological lifespan (CLS) of budding yeast is a model for the aging of post-mitotic cells in higher eukaryotes. We report here the development of a new method to assess yeast CLS. The new assay is simple, convenient and labor-saving. We applied this new method to screen natural compounds isolated from mushrooms and discovered beauveriolide I as a potent anti-aging agent.

There is considerable interest in identifying small, drug-like compounds that slow aging in multiple species, particularly in mammals. Such compounds may prove to be useful in treating and retarding age-related disease in humans. Just as invertebrate models have been essential in helping us understand the genetic pathways that control aging, these model organisms are also proving valuable in discovering chemical compounds that influence longevity.

Long non-protein coding RNAs (lncRNAs) are an important class of molecules that help orchestrate key cellular events. Although their functional roles in cells are not well understood, thousands of lncRNAs and a number of possible mechanisms by which they act have been reported. LncRNAs can exert their regulatory function in cells by interacting with epigenetic enzymes. In this study, we developed a tool to study lncRNA-protein interactions for high-throughput screening of small-molecule modulators using AlphaScreen technology.

The growing drug resistance of Plasmodia spp. to current antimalarial agents in the quinine and artemisinin families further asserts the need for novel drug classes to combat malaria infection. One approach to the discovery of new antimalarials is the screening of natural product extracts for activity against the formation of hemozoin, a biomineral essential to parasite survival. By mimicking the in vivo lipid-water interface at which native hemozoin is found, hemozoin can be synthesized outside the parasite.

This research describes the use of novel antimalarial combinations of the new artemisinin derivative artemiside, a 10-alkylamino artemisinin. It is a stable, highly crystalline compound that is economically prepared from dihydroartemisinin in a one-step process. Artemiside activity was more pronounced than that of any antimalarial drug in use, both in Plasmodium falciparum culture and in vivo in a murine malaria model depicting cerebral malaria (CM).

The emergence and spread of multidrug-resistant Plasmodium falciparum and recent detection of potential artemisinin-resistant strains in Southeast Asia highlight the importance of developing novel antimalarial therapies. Using a previously generated stable transgenic P. falciparum line with high-level firefly luciferase expression, we report the adaptation, miniaturization, optimization, and validation of a high-throughput screening assay in 384-well plates. Assay conditions, including the percentage of parasitemia and hematocrit, were optimized.

Most current antimalarials for treatment of clinical Plasmodium falciparum malaria fall into two broad drug families and target the food vacuole of the trophozoite stage. No antimalarials have been shown to target the brief extracellular merozoite form of blood-stage malaria. We studied a panel of 12 drugs, 10 of which have been used extensively clinically, for their invasion, schizont rupture, and growth-inhibitory activity using high-throughput flow cytometry and new approaches for the study of merozoite invasion and early intraerythrocytic development.

Assessment of in vitro susceptibility is a fundamental component of antimalarial surveillance studies, but wide variations in the measurement of parasite growth and the calculation of inhibitory constants make comparisons of data from different laboratories difficult. Here we describe a Web-based, high-throughput in vitro analysis and reporting tool (IVART) generating inhibitory constants for large data sets.